Global shipping, such as of drilling rig components and systems, necessarily involves large fabricated structures. The structures often require the assistance of cranes for transportation. Most structures have lift-eyes that enable cranes and other transportation devices to connect to and carry the structures during operation.
Shipping costs of the fabricated structures are often based on the total volume occupied by the structures. Conventional lift-eyes are attached externally to the fabricated structures. Such a configuration increases the overall volume occupied by each container because the protruding lift-eyes prevent the structures from seamlessly stacking end to end.
FIG. 1 is a perspective view of a first conventional fabricated structure 100 and a second conventional fabricated structure 110 with a plurality of protruding lift-eyes 115a, 115b, 115c, 115d, 115e, 115f. The protruding lift-eye 115a adds to the total volume occupied by each container by an amount equal to the height, h, of the protruding lift eye 115a multiplied by the length, l, and width, w, of either fabricated structure 100, 110 because the first conventional fabricated structure 100 cannot be stacked directly atop the second conventional fabricated structure 110. This additional volume forces companies to pay increased shipping costs without obtaining any additional storage capacity.
Other lift-eyes do not protrude from the fabricated structure and may, instead, be stored within the structure. However, these lift-eyes are stowed within the interior of the fabricated structure and therefore occupy available space that would otherwise be available for occupation by the systems and components requiring space. Therefore, companies must design larger fabricated structures to meet the needs of some structures.
Further, many fabricated structures are limited in the loads they can handle because the lift-eyes installed in them are only capable of withstanding certain conditions and loads. This limitation requires some companies to design for larger, heavier fabricated structures, although they do not require the extra volume, because the larger structures have more durable lift-eyes.
The present disclosure provides a lift-eye in pocket apparatuses and methods to overcome some of the disadvantages of conventional fabricated structures, as further disclosed below.